JP5789274B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire in which a decorative pattern is formed on the surface of a sidewall portion.

  Generally, the sidewall portion of a pneumatic tire is covered with a small thickness of rubber. For this reason, local irregularities called bulges and dents are likely to appear on the sidewall portions due to the seams of the carcass that is the internal structural material of the tire, residual air, and the like.

  Conventionally, in order to make such unevenness inconspicuous, there has been proposed a pneumatic tire in which a decorative pattern extending along the tire circumferential direction is formed on the surface of the sidewall portion (for example, Patent Document 1 below). A typical decorative pattern is also called a serration pattern, and a linear pattern extending in the tire radial direction is repeatedly arranged in the tire circumferential direction.

JP 2010-254088 A

  However, the conventional decorative pattern is a monotonous pattern, and there is a problem that the blinding effect that makes the unevenness inconspicuous cannot be sufficiently exhibited.

  The present invention has been devised in view of the above problems, and has as its main object to provide a pneumatic tire that can improve the blinding effect of making the unevenness of the sidewall portions inconspicuous.

Among the present inventions, the invention described in claim 1 is a pneumatic tire in which a strip-shaped decorative pattern extending along the tire circumferential direction is formed on the surface of the sidewall portion, and the decorative pattern is a unit pattern. Are arranged repeatedly, a plurality of substantially polygonal patterns that form a similar shape are concentrically arranged, and each contour of the plurality of polygonal patterns is a convex that continues over the entire circumference, Alternatively, it is characterized in that it is formed with a concave continuous over the entire circumference .

  The invention according to claim 2 is the pneumatic tire according to claim 1, wherein the decorative pattern is such that the unit patterns are arranged in a tire circumferential direction.

  The invention according to claim 3 is the pneumatic tire according to claim 1 or 2, wherein the decorative pattern is such that the unit patterns are arranged in a tire radial direction.

  The invention according to claim 4 is the pneumatic tire according to any one of claims 1 to 3, wherein the substantially polygonal pattern is a triangular, quadrangular or hexagonal pattern.

  The invention according to claim 5 is the pneumatic tire according to any one of claims 1 to 3, wherein the substantially polygonal pattern is a square pattern.

The invention described in claim 6, wherein each unit pattern is the unit claims plurality of adjacent vertices of the substantially polygonal pattern contained in pattern are connected with a straight line pattern, respectively 1 to 5 A pneumatic tire according to any one of the above.

The invention according to claim 7 is the pneumatic tire according to claim 1 , wherein the decorative pattern is arranged in an arbitrary tire radial direction passing through a tire rotation axis in a tire side view. .

In the invention according to claim 8 , the decorative pattern is arranged in an arbitrary tire radial direction passing through a tire rotation axis and an orthogonal direction orthogonal to the tire radial direction in the tire side view. The pneumatic tire according to Item 1.

  The decorative pattern of the pneumatic tire of the present invention is formed by repeatedly arranging unit patterns, and the unit patterns are formed by concentrically arranging a plurality of substantially polygonal patterns having similar shapes. In such a decorative pattern, the outline of the substantially polygonal pattern and the outline of the unevenness of the sidewall portion overlap each other, making the unevenness inconspicuous. Therefore, in the present invention, it is possible to provide a pneumatic tire in which the unevenness of the sidewall portion is less noticeable.

It is the side view to which the principal part of the pneumatic tire of this embodiment was expanded. It is AA sectional drawing of the side wall part of FIG. It is an enlarged plan view of a decorative pattern. It is an enlarged plan view of a unit pattern. (A) is an A1-A1 end view of FIG. 4, and (B) is an A2-A2 end view of FIG. 4. It is the side view to which the principal part of the pneumatic tire which shows other embodiment of this invention was expanded. It is an enlarged plan view of a decorative pattern according to another embodiment of the present invention. It is an enlarged plan view of a decorative pattern according to another embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows an enlarged side view of a pneumatic tire (hereinafter, sometimes simply referred to as “tire”) 1 of the present embodiment. FIG. 2 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIG. 1, a decorative pattern 3 is formed on the surface 2S of the sidewall portion 2 of the tire 1.

  As shown in FIG. 2, the sidewall portion 2 includes, for example, a carcass 6 and a sidewall rubber 2 </ b> G disposed on the outer side in the tire axial direction of the carcass 6. The sidewall rubber 2G forms the surface 2S of the sidewall portion 2.

  As shown in FIG. 1, the decorative pattern 3 has a strip shape extending along the tire circumferential direction. The belt shape includes both an annular shape continuously extending in the tire circumferential direction and an arc shape forming a part in the tire circumferential direction. Since irregularities such as bulges and dents may occur in the entire range of the surface 2S of the sidewall portion 2, the decorative pattern 3 is desirably formed in an annular shape that is continuous in the tire circumferential direction.

  The decorative pattern 3 is a pattern formed on the sidewall rubber 2G by, for example, coloring, vulcanization molding or cutting. From the viewpoint of durability and productivity, the decorative pattern 3 of the present embodiment is composed of an uneven pattern formed on the sidewall rubber 2G by vulcanization molding.

  Outer ribs 7a and inner ribs 7b extending in the tire circumferential direction are formed on both sides of the decorative pattern 3 in the tire radial direction. The outer rib 7a and the inner rib 7b each protrude outward in the tire axial direction. The outer rib 7a and the inner rib 7b reinforce the sidewall portion 2 so as to suppress the occurrence of cracks and the like starting from both ends of the decorative pattern 3 in the tire radial direction.

  FIG. 3 shows an enlarged plan view of the decorative pattern 3 of FIG. As shown in FIG. 3, the decorative pattern 3 is formed by repeatedly arranging unit patterns 8. In FIG. 3, one unit pattern 8 is shown lightly colored for easy understanding. In the decorative pattern 3 of the present embodiment, a plurality of unit patterns 8 are arranged in the tire circumferential direction and the tire radial direction, respectively.

  The unit pattern 8 is formed by concentrically arranging a plurality of substantially polygonal patterns 9 having a similar shape. In such a decorative pattern 3, the unevenness of the sidewall portion 2 and the outline 11 of the substantially polygonal pattern 9 overlap, whereby the unevenness can be made inconspicuous. Therefore, the present invention can provide the tire 1 in which the unevenness of the sidewall portion 2 is not noticeable.

  The substantially polygonal pattern 9 of the present embodiment is a rectangular pattern. The strip-shaped decorative pattern 3 can be easily formed by repeatedly arranging a rectangular pattern. The rectangular pattern is preferably a rectangular pattern or a square pattern.

  Regarding the substantially polygonal pattern 9, the “similar shape” includes a mathematically strict similarity mode, but includes a shape that gives a sense of similarity at first glance when the tire is observed with the naked eye from the outside. . Since the surface 2S of the typical sidewall portion 2 is a three-dimensional smooth convex curved surface, it is difficult to form a strict similar pattern.

  The “substantially polygonal pattern” includes a mathematically strict polygonal form, but includes a form that gives a sense of polygonal appearance when the tire is observed with the naked eye from the outside. Since the surface 2S of the typical sidewall portion 2 is a three-dimensional smooth convex curved surface, it is difficult to form a strict polygon thereon. For example, a polygon is originally a figure surrounded by straight sides, but includes a shape in which one or more sides are formed by arcs along the tire circumferential direction.

  From the same viewpoint as described above, the “concentricity” includes a mode in which the centers are strictly coincident, but includes a mode that gives a sense of concentricity when the tire is observed with the naked eye from the outside. It is.

  The unit pattern 8 includes a plurality of substantially polygonal patterns 9. In order to enhance the blinding effect, the number of substantially polygonal patterns 9 included in the unit pattern 8 is preferably 2 or more, more preferably 3 or more, and further preferably 4 or more. In order to suppress a decrease in productivity, the number of substantially polygonal patterns 9 included in the unit pattern 8 is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less.

  The substantially polygonal pattern 9 of the present embodiment includes a first pattern 9A located on the most central side of the unit pattern 8, a second pattern 9B on the outer side, a third pattern 9C on the outer side, and a fourth pattern on the outermost side. And a pattern 9D.

  FIG. 4 shows an enlarged view of the unit pattern 8 of FIG. 5A shows an end view of A1-A1 in FIG. 4, and FIG. 5B shows an end view of A2-A2 in FIG. In this embodiment, the outline 11 of the substantially polygonal pattern 9 is formed by, for example, a convex portion 12 protruding outward in the tire axial direction. The outline 11 of the substantially polygonal pattern 9 may be formed by a concave portion (not shown) such as a groove recessed inward of the tire radius in place of the convex portion 12 or together with the convex portion 12.

  The substantially polygonal pattern 9 in which the contour 11 is composed of the convex portion 12 (or the concave portion) creates a portion that appears bright and a portion that appears dark on the surface 2S of the sidewall portion 2 due to reflection of light from the outside. As a result, the contour of the unevenness of the sidewall portion 2 can be further blurred, and the effect of blindfolding the unevenness is further improved.

  As shown in FIG. 4, in order to further enhance the above-described blinding effect, the length W1 in the tire circumferential direction and the length L1 in the tire radial direction of the smallest substantially polygonal pattern 9 (first pattern 9A) are preferably Is 2 mm or more, more preferably 3 mm or more, preferably 10 mm or less, more preferably 8 mm or less.

  In order to obtain a substantially polygonal pattern 9 with good visibility without impairing productivity or the like, the width W2 of the outline 11 of the substantially polygonal pattern 9 (in this embodiment, the width of the convex portion 12) is 0.3 to. 1.0 mm is desirable. Such a substantially polygonal pattern 9 can exhibit a better blinding effect. When the width W2 of the contour 11 is less than 0.3 mm, it is difficult to form the substantially polygonal pattern 9 and the productivity may be reduced. Conversely, if the width W2 of the contour 11 exceeds 1.0 mm, the blinding effect may be reduced.

  Similarly, in order to obtain a substantially polygonal pattern 9 with good visibility without impairing productivity or the like, as shown in FIG. 4, the sides of the substantially polygonal pattern 9 arranged concentrically (in this example, convex portions) The distance P between 12) is preferably 0.5 to 3.0 mm.

  As shown in FIG. 5A, the height H1 of the convex portion 12 (depth in the case of the concave portion) is preferably 0.1 to 0.5 mm. When the height H1 is less than 0.1 mm, the blinding effect by the substantially polygonal pattern 9 may be reduced. Conversely, when the height H1 is greater than 0.5 mm, the durability of the convex portion 12 may be reduced. From such a viewpoint, the height H1 is more preferably 0.2 to 0.4 mm.

  As shown in FIG. 3 or FIG. 4, the unit pattern 8 of the present embodiment is such that adjacent vertexes 13 of a plurality of substantially polygonal patterns 9 included in the unit pattern 8 are connected by a linear pattern 14. ing. In the present embodiment, four linear patterns 14 extending in an X shape from the four vertices 13 of the first pattern 9A to the four vertices of the fourth pattern 9D are provided. Such a linear pattern 14 complicates the pattern shape without impairing the regularity of the unit pattern 8.

  Such a linear pattern 14 can blur the unevenness of the sidewall portion 2 by the same action as the contour 11 of the substantially polygonal pattern 9, and can further improve the blinding effect. The unit pattern 8 of this embodiment includes a linear component extending in the tire radial direction, a linear component extending in the tire circumferential direction, and a linear component that is inclined in both the tire radial direction and the tire circumferential direction. Such a unit pattern further improves the blinding effect in that the opportunity to overlap the contour of the unevenness of the sidewall portion 2 further increases. Moreover, as FIG. 3 shows, the linear pattern 14 can raise the continuity of the adjacent unit patterns 8, and can improve the aesthetic quality of the tire 1. FIG.

  The linear pattern 14 is preferably formed by, for example, a convex portion protruding outward in the tire axial direction or a concave portion recessed inward in the tire axial direction. As shown in FIG. 5B, the linear pattern 14 of the present embodiment is formed by convex portions.

  The width W3 of the convex portion is preferably 0.3 to 1.0 mm, more preferably 0.6 to 0.8 mm, from the same viewpoint as the width W2 of the convex portion 12. The width W3 of the convex portion may be larger than the width W2 of the convex portion 12 within the above range.

  As shown in FIG. 5B, the height H3 of the convex portions forming the linear pattern 14 is preferably 0.1 to 0.5 mm, similar to the height H1 of the convex portions 12. More preferably, it is 0.2 to 0.4 mm.

  When the decorative pattern 3 of the sidewall portion 2 is molded by a vulcanization mold, the contour 11 or the linear pattern 14 formed of a convex portion is formed by a groove-shaped molding portion of the vulcanization mold. Such a molded part functions as a vent line for discharging air. Therefore, it is also useful for preventing bareness on the surface of the sidewall portion 2. In this case, it is preferable that the contour 11 or the linear pattern 14 formed as the convex portion is formed with a spew extending outward in the tire axial direction or a cut scar (not shown). The spew is a rubber molded with vent holes extending from the vent line to the outside of the mold. Accordingly, the contour 11 or the linear pattern 14 formed as a convex portion is provided with spew or a cut mark thereof, so that the air between the decorative pattern 3 and the vulcanization mold can be removed from the vulcanization mold. It can be effectively discharged from the hole. Therefore, the decorative pattern 3 is accurately formed. In addition, molding defects such as bear caused by air remaining between the sidewall portion 2 and the vulcanization mold can be reduced.

FIG. 6 shows a decorative pattern 3 according to another embodiment of the present invention.
In this embodiment, the decorative pattern 3 is arranged in the tire radial direction T1 in which all the unit patterns 8 pass through the tire rotation axis CL in the tire side view. In such a decorative pattern 3, a substantially polygonal pattern 9 in which each side is closer to a straight line can be used. Therefore, the processing of the decorative pattern 3 is easy.

  In the decorative pattern 3 of the embodiment of FIG. 6, the unit patterns 8 are arranged not only in the tire radial direction T1 but also in the orthogonal direction T2 orthogonal to the tire radial direction T1 in the tire side view. Such a decorative pattern 3 can also be expected to have the same function and effect as in the above embodiment.

FIG. 7 shows a decorative pattern 3 according to another embodiment of the present invention.
In this embodiment, the substantially polygonal pattern 9 is composed of a triangular pattern 17. That is, the unit pattern 8 has a plurality of triangular patterns 17 having similar shapes arranged concentrically. In this embodiment, the unit patterns 8 are arranged so as to be staggered vertically in the tire radial direction. Thereby, the decorative pattern 3 has the unit patterns 8 arranged without gaps in the tire radial direction and the tire circumferential direction as in the embodiment of FIG. Such a decorative pattern 3 can also increase the blinding effect by making the pattern shape more complicated.

FIG. 8 shows a decorative pattern 3 according to still another embodiment of the present invention.
In this embodiment, the substantially polygonal pattern 9 is composed of a hexagonal pattern 18. That is, the unit pattern 8 includes a plurality of hexagonal patterns 18 that are similar to each other and are concentrically arranged. Such a decorative pattern 3 can also increase the blinding effect by making the pattern shape more complicated.

  Furthermore, the decorative pattern 3 may be configured by arranging different unit patterns 8 in which, for example, a triangular pattern 17, a quadrangular pattern 10, or a hexagonal pattern 18 are arranged concentrically in the tire radial direction and the tire circumferential direction. .

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited to these embodiment, It can deform | transform and implement in a various aspect.

  A pneumatic tire having a decorative pattern (size 195 / 65R16) was prototyped and tested for performance based on the specifications in Table 1.

In addition, for comparison, a comparative tire (comparative example) including a linear convex portion having a decorative pattern extending in the tire radial direction was prototyped and similarly tested.
Each test method is as follows.

<Blindfold performance>
About the sidewall part of each test tire, irregularities such as bulges and dents were confirmed with the naked eye, and the distinctiveness of the irregularities was evaluated by a five-point method based on the sensory function. The evaluation means that the larger the score, the more the unevenness cannot be identified.

<Appearance of decorative pattern>
The decorative pattern formed on the sidewall portion of each test tire was confirmed with the naked eye, and the appearance was evaluated by a five-point method according to the aesthetic sense of the tester. Evaluation shows that the appearance of a decorative pattern is excellent, so that a score is large.

  As a result of the test, it was confirmed that the tires of the examples were excellent in the blinding effect and appearance.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Side wall part 2S Surface 3 Decoration pattern 8 Unit pattern 9 Substantially polygonal pattern

Claims (8)

A pneumatic tire in which a band-shaped decorative pattern extending along the tire circumferential direction is formed on the surface of the sidewall portion,
The decorative pattern is composed of repeated unit patterns,
The unit pattern is a concentric arrangement of a plurality of substantially polygonal patterns having similar shapes,
Each of the outlines of the plurality of polygonal patterns is formed of a convex continuous over the entire circumference or a concave continuous over the entire circumference .   The pneumatic tire according to claim 1, wherein the decorative pattern includes the unit patterns arranged in a tire circumferential direction.   The pneumatic tire according to claim 1 or 2, wherein the decorative pattern includes the unit patterns arranged in a tire radial direction.   The pneumatic tire according to any one of claims 1 to 3, wherein the substantially polygonal pattern is a triangular, square, or hexagonal pattern.   The pneumatic tire according to claim 1, wherein the substantially polygonal pattern is a square pattern.   The pneumatic tire according to any one of claims 1 to 5, wherein each of the unit patterns is formed by connecting adjacent apexes of the plurality of substantially polygonal patterns included in the unit pattern in a straight line pattern.   2. The pneumatic tire according to claim 1, wherein the decorative pattern is arranged in an arbitrary tire radial direction in which the unit pattern passes through a tire rotation axis in a side view of the tire. 2. The pneumatic tire according to claim 1, wherein the decorative pattern is arranged in an arbitrary tire radial direction passing through a tire rotation axis and an orthogonal direction orthogonal to the tire radial direction in a side view of the tire.

Images